The present disclosure relates to a fusing device to fuse a toner image to a sheet and an image forming apparatus to which the fusing device is applied.
Fusing devices for image forming apparatuses include a fusing nip part formed in a manner that a fusing roller is in press contact with a pressure roller. Pressure and heat are applied to a sheet when the sheet passes through the fusing nip part, thereby fusing to the sheet a toner image transferred to the sheet. Incidentally, toner melted after the sheet passes through the fusing nip part may form an adhesive layer. This may cause the sheet to adhere to the peripheral surface of the fusing roller. In this case, the sheet may wind around the fusing roller. In order to prevent such winding, a separation member is provided downstream of the fusing nip part in the rotation direction of the fusing roller. The separation member is arranged close to the fusing roller to separate the sheet, which starts winding to the fusing roller, from the fusing roller.
The separation member includes a plate-shaped member extending in the axial direction of the fusing roller. Where the tip end of the plate-shaped member is always in contact with the peripheral surface of the fusing roller, the peripheral surface of the fusing roller may be scared. If a toner image is fused to a sheet with the use of the fusing roller of which peripheral surface is scared, the scar may appear on the toner image. This scar may cause an image defect. For this reason, a gap is left between the tip end of the plate-shaped member and the peripheral surface of the fusing roller. This gap is formed with the use of an abutting member mounted on the end of the separation member. The known abutting member is always in contact with the peripheral surface of the fusing roller in a non-sheet passing region of the fusing roller.